Direct answer: IRS Statistics of Income (SOI) tables show how many returns claim the mortgage interest deduction in a geography. After higher standard deductions, far fewer filers itemize than before 2018 — so “everyone deducts mortgage interest” is no longer a safe assumption.
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See _docs/data-refresh/gov-data-refresh-calendar.md for the annual SOI ZIP pull. Outreach targets: _docs/backlink-content/backlink-outreach-finance-gov-data-2026.md.
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Last reviewed: · Source: IRS Statistics of Income (SOI)
Frequently Asked Questions
What is IRS SOI data on mortgage interest?
The IRS Statistics of Income (SOI) program publishes aggregated tax-return statistics, including counts and amounts for the mortgage interest deduction by geography (often ZIP or county in selected tables). These are historical filing patterns, not advice on whether you should itemize.
Does claiming mortgage interest always beat the standard deduction?
No. After the Tax Cuts and Jobs Act raised the standard deduction, many homeowners no longer itemize. Whether mortgage interest plus property taxes and other itemized amounts exceed the standard deduction depends on your filing status and totals. Use IRS Publication 936 concepts and a tax professional for personal decisions.
Will Daily Calcs publish a ZIP CSV?
Yes — after the next SOI ZIP extract is processed into /data/reports/, this page will link the file and list share-of-filers claiming mortgage interest for covered ZIPs. Until then, treat this as a methodology and planning guide tied to IRS SOI publications.
How does this relate to property taxes?
Property taxes and mortgage interest are both common Schedule A items (subject to SALT caps and other rules). Our Property Tax Calculator estimates local tax escrow; SOI context shows how often filers in an area historically itemized related deductions.
Is this tax advice?
No. Daily Calcs provides planning estimators and public-data explainers. Tax outcomes depend on your full return. Confirm with IRS publications or a qualified tax professional.
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